where"s your bung hole?

[MOTORHEAD]

Looks like I'm going to need an A/F meter to get the webers dialed in, either portable or fixed mount. If you have or used one, where did you install the o2 sensor bung? I have installed a few just under in the collector and aimed inboard, but just read that the sensor should be upright so it doesn't get contaminated. How's yours working ?

[blykins]

Hahaha, he said bung hole.

[RICK LAKE]

Motorhead, the best setup is Innovate wide band setup. you want the LM-2 kit. They have clips that will hold in the tail pipe so you get a complete mix of exhaust system. Cylinder #7, I was told is the weakest cylinder with lowest flow to it. I have my bung in this pipe for readings. If you are really serious about this, there is an 8 cylinder o2 sensor kit with data log for checking the motor. With the motor running hot, checking the exhaust pipes EGT'S about 6" from the head will also give you some ideas as to how each cylinder is running. This is a very time consuming thing to do, but in the end, you are going to get max power and preformance from the webers. There should be a couple of guys on the forumn that can give you the tubes, bleeds and jets they use in their setup. the different will be camshafts and lSA reading. Webers like a 114-116 LSA to stop reversion in the carbs. The other thing is air flow to the back carbs. A air box at speed will help pressurize the carbs and get better air to all. The air get dirty the farther back in the box with turbulance. Some guys put small flaps inside the air box to redirect the flow into the inlet horns of the carbs. I set of webers will make 10-25 hp and about 8-20 ft of torque more than a single carb in the mid range of the motor. Good luck Rick L.

[MOTORHEAD]

Brent : Glad someone got a chuckle !
Rick: My cam is a hyd roller spec'd by Barry R. specifically for webers. Current jetting is from Jim Inglese. It's close, but to get it dialed in I think i need a A/F monitor. I have a new wide band sensor & gauges are fairly cheap. I mainly need to know where is the best place for the sensor bung to be welded in. Ideally its in the collector, but on top, vertically, which isn't going to look very good! I've installed a few at about 3-4 o'clock to the inboard. but those tend to get contaminated internally.

[Luce]

bung hole. huhu huhu huhu

It's less than optimal, but looks OK. I'm not running closed loop, but I used it to self tune. I don't need immediate readings, but the needle still moved faster than you can read it. Works so far...

[MOTORHEAD]

Luce: are you using wide or narrow band?
My only problem with the sensor being horizontal to inverted is accumulation of contamination which eventually renders the sensor inop. However I think the solution for me is to go ahead and mount it horizontal, with wires headed underbody, use it for tuning, then remove it and plug hole. Yeah, thats the ticket! thanks for the pic.

[Luce]

Yea, that's the inovative wide band o2. I knew it may end up crapped out, but I'll be tuned before it gives out I hope. It's in a big open wart of a pocket off to the side of the collector. I was expecting a slow response, but it responds better than I hoped. (maybe .2 sec lag)

It has 1100 miles on it so far. I was also thinking if it fouled out, I might add a heat retainer out of header wrap or something. Keeping it hot is the issue. (from what I understand)

[Luce]

I made those side pipes myself from a $90 jegs header kit, 2-$30 Jones 3" open mufflers, and a $25 3.5" U pipe I sliced to make the turn outs. I wasn't sure how much noise I wanted to tolerate, so I didn't want to be $1800 into some nice stainless pipes that were too loud or too restrictive. Turns out, I like the loud.

[Derald Rice]

I use the LM-2 when I tune my webers, and the bungs are behind the collectors, and in front of the mufflers. They are mounted as high as possible so that I can still get to the sensors, but they are not where innovate wanted them to be. On the driver side, looking from the front, this means its at approx an 8 o'clock, and on the pass, it's at about a 4 o'clock. When the sensors are out, and the plugs are in, the bung is visible if you really look for it, but it's not that obvious.

I only use the sensors for tuning, so they are not in for very long, and I have not had any problems with any contamination. Can't remember that last time that I did any tuning.

[Gaz64]

O2 sensors should be mounted above horizontal to keep the moisture out of the sensor. As stated by many sensor manufacturers.

[Tom Howland]

Yes, they should be mounted at 12 o'clock. I have my LM-2 sensors at 4 and 8 o'clock so they won't be seen. They haven't fouled out yet after 3 years. I only have them in when tuning though. I think I read the sensor can be cleaned with a gas torch. I have not tried that.

[MOTORHEAD]

Tom and Derald: I see you're using sensors on both sides. How well does that work for tuning the webers? Yeah, if you don't leave them in all the time, the mounting position should not be an issue.